Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L9/00—Disinfection, sterilisation or deodorisation of air
  • A61L9/015—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone
  • A61L9/04—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone using substances evaporated in the air without heating
  • A61L9/048—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone using substances evaporated in the air without heating air treating gels
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L9/00—Disinfection, sterilisation or deodorisation of air
  • A61L9/015—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone
  • A61L9/04—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone using substances evaporated in the air without heating
  • A61L9/046—Disinfection, sterilisation or deodorisation of air using gaseous or vaporous substances, e.g. ozone using substances evaporated in the air without heating with the help of a non-organic compound

Definitions

• the invention relates to a process for the preparation of air-freshener gels.
• Air-freshener gels are popular consumer products. They consist of a perfume containing carrier material, from which the perfume evaporates slowly and thus gives a pleasant smell to the atmosphere. The life time and the amount of perfume emitted per time unit are determined mainly by the amount of perfume in the air-freshener.
• gelled water is used as carrier material. Because perfumes are generally not or hardly soluble in water they should be dispersed therein as homogeneously as possible.
• gelled organic solvents like monohydric or polyhydric alcohols or glycol ethers are used as carrier materials. However, water has the advantage of being cheap and toxicologically unsuspected.
• Aqueous gels may be prepared in many ways known as such using as gelling agent e.g.: vegetable gums like carragheenin, agar agar, alginates, pectine, guar gum, tragacanth, karaya gun, xanthan etc. and further for instance gelatin as well as starch and cellulose derivatives.
• gelling agent e.g.: vegetable gums like carragheenin, agar agar, alginates, pectine, guar gum, tragacanth, karaya gun, xanthan etc. and further for instance gelatin as well as starch and cellulose derivatives.
• the gel strength can be increased by the addition of salts of bivalent or polyvalent metals like Ca, Mg, Al or Cr.
• synthetic polymers like polyvinyl alcohol may be used as gelling agent.
• aqueous perfume gels have the disadvantage that they only may contain a limited amount of perfume.
• a perfume content of more than about 6% strongly reduces the gel strength and/or causes syneresis whereby the perfume leaves the gel as a liquid.
• Aqueous perfume gels are described for instance in the published Japanese patent applications No. 54,110,990 (gelling agent: carragheenin and sodium stearate, perfume content up to 6%); No. 53,088,334 (gelling agent: bacterial polysaccharide, 1-10% of perfume); and No. 52,136,893 (gelling agent: carragheenin and polyvinyl alcohol, 2-4% of perfume), and in the French patent application No. 2,293,976 (gelling agent: carboxymethyl cellulose/Al-salt, 5% of perfume).
• Dutch patent application No. 76,11041 also discloses the use of carboxymethyl cellulose and salts of trivalent metals as gelling agents in aqueous perfume gels. Although it is mentioned in the specification that these gels may contain up to 20% of perfume the examples only illustrate a perfume content of 4%. Likewise Dutch patent application No. 76,02254 discloses similar aqueous perfume gels which would contain up to 10% of perfume whereas in the examples only gels are illustrated containing up to 2.5% of perfume. Dutch patent application No. 75,02596 describes aqueous gels based on mixtures of carragheenin and locust bean gum which according to the specification may also contain up to 10% of perfume, however, from the examples it appears that no more than 3.3% of perfume is used.
• Dutch patent application No. 76,12909 discloses gels based on amylose as gelling agent.
• the perfume content of these gels is 0.25-30% perferably 0.5-5%. It is true that one of the examples discloses a gel containing 30% of perfume, however, for that result a content of 10% of pure (and therefore expensive) amylose is required.
• starch containing 70% of amylose no stable gel can be produced yet with even 10% of perfume.
• these gels have the disadvantage that for the preparation of the necessary amylose-solution high temperatures (up to 170° C.) and pressures (up to 7 atm) are required and therefore relatively complicated equipment.
• the perfume is used together with an amount of emulsifier for promoting the homogeneous distribution of the perfume in the aqueous phase.
• aqueous gels cannot contain more than 2-3% of perfume unless a non-ionogenic emulsifier is added in a amount of 0.5-1.5 times the amount of perfume, in which case the perfume content of the gel may rise to 10%.
• the amount of perfume which can be distributed homogeneously in an aqueous gel highly depends on the solubility of the perfume in water and thus on the type of the components composing the perfume.
• perfume is used to mean a mixture of organic compounds like aldehydes, ketones, nitriles, esters, carboxylic acids, alcohols, ethers etc. which may also contain natural products like essential oils, resinoids, balsams, concretes etc. This mixture is meant to emit a desired smell.
• a perfume contains a mostly small amount of a solvent or diluent usual in perfumery, for instance because one or more of the components used in the composition are only available or manageable in solution.
• the purpose of the invention is to provide aqueous air-freshener gels having an increased perfume content and for that reason a longer lifetime and/or a higher perfume emission per time unit.
• increased perfume content means in this respect a content of at least 5% and preferably more than 10% based on the total weight of the gel.
• air-freshener gels can be prepared by previously mixing the perfume with specific solid inorganic carrier materials and then introducing this mixture, which hereinafter will be called “premix” in an aqueous gel.
• specific solid inorganic carrier materials are mentioned: magnesium oxide powder, active carbon, zeolites and absorption agents based on silicon dioxide (silica) like many kinds of silica gel, bentonite and especially hydrophobic or non-hydrophobic pyrogenic silica.
• mixtures consisting of solid materials can be used as far as they mainly consist of one or more of the above mentioned types of carrier materials.
• aqueous gels according to the invention can be prepared by using gelling agents known and usual for aqueous gels as for instance described in the already mentioned patent specifications and patent applications and the literature cited therein.
• very suitable gelling agents are for instance agar agar, carragheenin and modified cellulose like methyl cellulose, hydroxyethyl cellulose and carboxymethyl cellulose.
• Some gelling agents may advantageously be combined with a salt of a polyvalent metal as crosslinking agent.
• Part of the water used for preparing the gel can optionally be replaced by water miscible organic solvents like monohydric or polyhydric alcohols for instance ethanol, isopropanol, ethylene glycol etc. as far as these solvents do not affect the activity of the gelling agent. For economic reasons this replacement is generally not recommended because organic solvents are more expensive than water.
• the amount of perfume which is present in the air-freshener gel according to the invention is determined, on the one hand, by the amount of perfume in the premix and, on the other hand, by the amount of premix in the gel.
• This last amount is not subjected to any fundamental restriction but in practice is restricted by the fact that on preparing the gel mixture the viscosity increases with an increasing amount of premix. Therefore the maximum amount of premix to be used is determined by the demands made by the processing of the gel mixture during and after the preparation and the equipment which is available for the preparation. When the demand is made that the mixture directly after the preparation should be so liquid that it simply can be poured into molds, the maximum amount of the premix in the gel is about 35%. However, when for the preparation heavy duty stirring equipment is used and the gel packings are filled by means of equipment and operations under pressure, considerably higher premix contents are achievable.
• the maximum perfume content in the premix is determined by the requirement that the premix should be a solid mixture which optionally may be lumpy and feeling moist.
• the minimum amount of solid carrier material in the premix depends on the type of carrier material. It varies from about 60% for bentonite to about 10% for some highly porous kinds of pyrogenic silica. For active carbon and magnesium oxide the minimum contents are about 40% and about 30% respectively.
• emulsifiers When using active carbon or magnesium oxide as solid carrier material the addition of emulsifiers is not recommended because this affects the stability of the gels according to the invention. On the contrary, by using a zeolite or a carrier material based on silica it is necessary to previously mix the perfume homogeneously with a non-ionogenic emulsifier in an amount of 5-200%, calculated on the weight of the perfume.
• emulsifiers having a HLB-value of 9 or more are used such as esters of fatty acids and polyethylene glycols and condensation products of alkylphenols or fatty alcohols with ethylene oxide.
• the gel is prepared according to methods known per se for such products, except that the process of the invention differs from these methods in that the perfume is previously mixed with the solid carrier material according to the invention into a homogeneous mixture called premix.
• the carrier material is a zeolite or a carrier material based on silica the perfume is stirred homogeneously with a non-ionogenic emulsifier before said mixing stage.
• the ready premix is then mixed with the water, the gelling agent and optionally the metal salt, the preservative and the dye.
• Preferably water and gelling agent are mixed previously and then the premix is added as soon as possible.
• Some gel mixtures are preferably prepared at elevated temperatures and then at these temperatures poured into molds. After cooling to room temperature the gel mixture solidifies.
• Example I According to the method described in Example I 31.5 g of a somewhat moist feeling but solid premix was obtained from 25 g of the above mentioned perfume, 2.5 g of Arlypon NP-14 and 4 g of Aerosil. 45 g of aqueous dispersion was obtained by addition of water. 2.3 g of carragheenin, 2 g of chloroacetamide and 0.5 g of CaCl 2 .2H 2 O were dissolved at 75° C. in 52 g of water. The warm premix dispersion and carragheenin solution were mixed, stirred homogeneous and discharged into molds. After cooling to room temperature firm and stable air-freshener gels were obtained having a perfume content of 25%.
• Example I a premix was prepared from 20 g of perfume, 2 g of Arlypon NP-14 and 5 g of Aerosil.
• a gel solution was prepared by dissolving 4 g of agar agar in 62.8 g of boiling water. After cooling to about 70° C. 5 g of ethanol, 1 g of propylene glycol and 0.2 g of a 35% formaldehyde solution were added. Finally the above described premix was added, the mixture stirred homogeneous and poured into molds while warm. The air-freshener gels obtained after cooling had a perfume content of 20%.
• a premix was prepared by thoroughly mixing of 19 g of perfume with 11 g of magnesium oxide powder.
• a gel solution was prepared by dissolving 0.5 g of CaCl 2 .2H 2 O, 0.2 g of a 10% solution of 5-bromo-5-nitro-1.3-dioxane in propylene glycol (preservative) and 2.6 g of carragheenin in 66.7 g of water at 85° C. After the complete mixture was stirred homogeneous, the above described premix was added, the mixture was stirred homogeneous again and poured into molds while warm. The air-freshener gels obtained after cooling had a perfume content of 19%.
• Example IV The process of Example IV was repeated but now with a premix consisting of 15 g of perfume and 15 g of active carbon.
• the air-freshener gels obtained had a perfume content of 15%.

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• Health & Medical Sciences (AREA)
• Epidemiology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Disinfection, Sterilisation Or Deodorisation Of Air (AREA)
• Fats And Perfumes (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19840162

Family Applications (1)

Country Status (7)

Cited By (22)

Families Citing this family (6)

Citations (12)

Family Cites Families (1)

• 1982
  • 1982-08-20 NL NL8203275A patent/NL8203275A/nl not_active Application Discontinuation
• 1983
  • 1983-08-16 US US06/523,750 patent/US4561997A/en not_active Expired - Lifetime
  • 1983-08-18 EP EP83201214A patent/EP0105539B1/de not_active Expired
  • 1983-08-18 ES ES525014A patent/ES8500065A1/es not_active Expired
  • 1983-08-18 DE DE8383201214T patent/DE3364069D1/de not_active Expired
  • 1983-08-19 JP JP58150423A patent/JPS5955255A/ja active Granted
  • 1983-08-19 BR BR8304500A patent/BR8304500A/pt not_active IP Right Cessation

Patent Citations (19)

Non-Patent Citations (4)

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